title: Antibody responses to a spore carbohydrate antigen as a marker of nonfatal inhalation anthrax in rhesus macaques.
abstract: The Bacillus anthracis exosporium protein BclA contains an O-linked antigenic tetrasaccharide whose terminal sugar is known as anthrose (J. M. Daubenspeck et al., J. Biol. Chem. 279:30945-30953, 2004). We hypothesized that serologic responses to anthrose may have diagnostic value in confirming exposure to aerosolized B. anthracis. We evaluated the serologic responses to a synthetic anthrose-containing trisaccharide (ATS) in a group of five rhesus macaques that survived inhalation anthrax following exposure to B. anthracis Ames spores. Two of five animals (RM2 and RM3) were treated with ciprofloxacin starting at 48 hours postexposure and two (RM4 and RM5) at 72 h postexposure; one animal (RM1) was untreated. Infection was confirmed by blood culture and detection of anthrax toxin lethal factor (LF) in plasma. Anti-ATS IgG responses were determined at 14, 21, 28, and 35 days postexposure, with preexposure serum as a control. All animals, irrespective of ciprofloxacin treatment, mounted a specific, measurable anti-ATS IgG response. The earliest detectable responses were on days 14 (RM1, RM2, and RM5), 21 (RM4), and 28 (RM3). Specificity of the anti-ATS responses was demonstrated by competitive-inhibition enzyme immunoassay (CIEIA), in which a 2-fold (wt/wt) excess of carbohydrate in a bovine serum albumin (BSA) conjugate of the oligosaccharide (ATS-BSA) effected >94% inhibition, whereas a structural analog lacking the 3-hydroxy-3-methyl-butyryl moiety at the C-4" of the anthrosyl residue had no inhibition activity. These data suggest that anti-ATS antibody responses may be used to identify aerosol exposure to B. anthracis spores. The anti-ATS antibody responses were detectable during administration of ciprofloxacin.
authors.affiliation: Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia 30333, USA. ESaile@cdc.gov
authors.forename: Elke
authors.initials: E
authors.lastname: Saile
authors.forename: Geert-Jan
authors.initials: GJ
authors.lastname: Boons
authors.forename: Therese
authors.initials: T
authors.lastname: Buskas
authors.forename: Russell W
authors.initials: RW
authors.lastname: Carlson
authors.forename: Elmar L
authors.initials: EL
authors.lastname: Kannenberg
authors.forename: John R
authors.initials: JR
authors.lastname: Barr
authors.forename: Anne E
authors.initials: AE
authors.lastname: Boyer
authors.forename: Maribel
authors.initials: M
authors.lastname: Gallegos-Candela
authors.forename: Conrad P
authors.initials: CP
authors.lastname: Quinn
mesh_terms: D000818:Animals; D000881:Anthrax / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D002241:Carbohydrates / Q000276:immunology*; D008253:Macaca mulatta; D008562:Membrane Glycoproteins / Q000276:immunology*; D018419:Primate Diseases / Q000175:diagnosis* / Q000276:immunology; D017192:Skin Diseases, Bacterial; D013171:Spores, Bacterial / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; C470593:BclA protein, Bacillus anthracis; D002241:Carbohydrates; D008562:Membrane Glycoproteins